Applying for a retirement visa (multiple entry non immigrant OA visa) in your home country was once the best option for those aged 50 and over. Now with the mandatory insurance requirements that follow you at every yearly extension, the inability to travel easily to nearby countries with borders still mostly shut and the difficulty in getting a 2nd year on this visa free by exiting and re-entering just before the expiry date, difficult and costly, it doesn't represent the value that it did a few years ago. I would reccommend getting a single entry tourist visa which gives you 60 days in Thailand, you can extend this by 30 days. During this 90 day period you can apply for a non immigrant O visa inside Thailand based on being over 50 years old. You will have time to set up a Thai bank account and move the requisite funds into a Thai bank so that you qualify for a 12 month extension of stay ie 15 months (non O visa= 3 months plus 12 months extension of stay) ability to stay in Thailand for about 4,000 baht in fees. If you need further advice on how to apply for a non O visa (aka retirement visa) based on being over 50. You can ask questions in the Thai Visa Advice Facebook group or read the saved posts in that group that relate to this visa
It's useful if ordering food on Tuk, you can scan and transfer without having to have the exact cash. I always pay the vet with bank transfers so don't have to worry about having sufficient cash with me. If you go out shopping and have left your card at home, most shops of any size, will allow you to scan and pay with your phone. I have used it at the supermarket and at restaurants that don't want to touch cash. I have used it to transfer money to charities, pay for tickets to events, pay my monthly internet account, pay my rent, put credit on my phone, buy air tickets, train tickets and bus tickets in Thai baht. Using a Thai bank account at a point of sale reduces the losses in currency conversions incurred when using a foreign credit card
If you have had one heart attack it is unlikely that any insurance company here will cover future heart related incidents as you will be considered to have a pre-existing condition. Unless of course you have a private health insurance policy already, in the UK that will allow you to be covered overseas. Choose your insurance company carefully and read the fine print as unfortunately, although medical costs are lower here than in many other countries, if you have a major event that your insurance company refuses to cover, you could find yourself with some very large medical costs
yeah voluntourism or an animal experience whilst here as a tourist is not the same as the genuine volunteering that qualifies for a volunteer visa that NGOs and foundations with the correct status can acquire for their volunteers